The present invention generally relates to navigation in a medical procedure. Specifically, the present invention provides a system and method for hybrid tracking in surgical navigation.
Medical practitioners, such as doctors, surgeons, and other medical professionals, often rely upon tracking or navigation systems when performing a medical procedure. Such systems may provide positioning and/or orientation (“P&O”) information for a medical instrument or implant with respect to the patient or a reference coordinate system, for example. A medical practitioner may refer to the tracking system to ascertain the P&O of the medical instrument when the instrument is not within the practitioner's line of sight with regard to the patient's anatomy, or with respect to non-visual information relative to the patient. A tracking system may also aid in pre-surgical planning.
A tracking system allows the medical practitioner to visualize the patient's anatomy and track the P&O of the instrument. The medical practitioner may use the tracking system to determine when the instrument or implant is positioned in a desired location or oriented in a particular direction. The medical practitioner may locate and operate on, or provide therapy to, a desired or injured area while avoiding other structures. Increased precision in locating medical instruments within a patient may provide for a less invasive medical procedure by facilitating improved control over smaller, flexible instruments having less impact on the patient. Improved control and precision with smaller, more refined instruments may also reduce risks associated with more invasive procedures such as open surgery.
Tracking systems may be optical, ultrasonic, inertial, electromagnetic, or sonic, for example. Generally, each system includes its own advantages and disadvantages. For example, optical tracking is typically considered the most accurate tracking technology. However, optical tracking requires a line-of-sight. During the course of a surgical procedure, a line-of-sight path may become impossible to achieve. If the surgeon relies on optical tracking alone, navigation of the instrument or implant may be temporarily unavailable.
At such a point during a medical procedure, the surgeon may wish to employ another tracking technology, such as an electromagnetic tracking system. Electromagnetic tracking systems allow for a surgeon to track a position and/or orientation of one sensor relative to another, without requiring a line-of-sight. However, due to electromagnetic interference caused by, among other things, metal objects in the operating environment, electromagnetic tracking systems may not always be the most accurate of the available tracking systems. Thus, at another point during the procedure, the surgeon may wish to again switch from the electromagnetic tracking system to another system.
While some current systems and methods may allow for a surgeon to employ more than one tracking technology during a medical procedure, such systems and methods typically do not allow for a dynamic change of tracking technologies. In other words, most of such systems and methods may allow for a surgeon to determine, before a medical procedure begins, which tracking technologies are to be used during the procedure.
However, current systems and methods do not allow for a surgeon to switch from one tracking technology to another “on the fly.” In other words, at some point during a procedure, one or more unused tracking technologies may be more accurate than the currently used technology. At that point, the surgeon may wish to switch from the currently used technology to one or more of the unused technologies. The surgeon may therefore ensure that he or she is constantly and consistently utilizing one of the most accurate tracking systems available to the surgeon.
Thus, a need exists for a system and method for hybrid tracking in surgical navigation. Such a system and method can provide for dynamic switching between two or more tracking technologies during a medical procedure to assist in the accuracy of navigation during a medical procedure.